Current limiting circuit, current limiting chip and electronic device

Abstract

The present disclosure relates to a current limiting circuit, a current limiting chip and an electronic device. The current limiting circuit comprises: a first switch unit arranged between an input end of the current limiting circuit and an output end of the current limiting circuit; a ground branch comprising a plurality of electrical elements, one end of the ground branch being connected to the input end and the other end being grounded; and a second switch unit arranged between the input end and a control end of the first switch unit, the control end of the second switch unit being connected between any two electrical elements of the ground branch. The control end of the second switch unit is configured to control the second switch unit to be in a first state when a current between the input end and the output end is greater than a preset threshold, the first state being an open state or a conductive state. The control end of the first switch unit is configured to control the first switch unit to be in an open state when the second switch unit is in the first state.

Description

Technical Field

[0001] This disclosure relates to the field of current protection technology, specifically to a current limiting circuit, a current limiting chip, and an electronic device. Background Technology

[0002] Current limiting circuits are a key circuit structure widely used in electronic systems. Their main function is to limit the magnitude of current, prevent damage to components in the circuit due to excessive current, and thus ensure the stable and safe operation of the entire circuit system.

[0003] Current limiting circuits in related technologies often have low current limiting accuracy and low precision, and the device structure is relatively complex. Summary of the Invention

[0004] To overcome the problems existing in the related technologies, this disclosure provides a current limiting circuit, a current limiting chip, and an electronic device to solve the defects in the related technologies.

[0005] According to a first aspect of the present disclosure, a current limiting circuit is provided, the current limiting circuit comprising: The first switching unit is located between the input terminal and the output terminal of the current limiting circuit; A grounding branch includes multiple electrical components, one end of which is connected to the input terminal and the other end is grounded. The second switching unit is located between the input terminal and the control terminal of the first switching unit, and the control terminal of the second switching unit is connected between any two electrical components of the grounding branch. Wherein, the control terminal of the second switching unit is used to control the second switching unit to be in a first state when the current between the input terminal and the output terminal is greater than a preset threshold, wherein the first state is an open state or an on state; the control terminal of the first switching unit is used to control the first switching unit to be in an open state when the second switching unit is in the first state.

[0006] In some embodiments of this disclosure, the control terminal of the second switching unit is used to control the second switching unit to be in a second state when the current between the input terminal and the output terminal is not greater than a preset threshold, wherein the second state is an on state or an off state; the control terminal of the first switching unit is used to control the first switching unit to be in an on state when the second switching unit is in the second state.

[0007] In some embodiments of this disclosure, a first resistor is further provided between the input terminal and the grounding branch.

[0008] In some embodiments of this disclosure, the grounding branch includes a second resistor and a third resistor connected in series, and the control terminal of the second switching unit is connected between the second resistor and the third resistor.

[0009] In some embodiments of this disclosure, the control terminal of the first switching unit is connected to a fourth resistor, and the end of the fourth resistor furthest from the first switching unit is grounded.

[0010] In some embodiments of this disclosure, the current limiting circuit further includes a third switching unit, which is disposed between the control terminal of the second switching unit and ground. The control terminal of the third switching unit is connected to the controller and is used to control the third switching unit to be in an on or off state based on the controller's instructions. The control terminal of the second switching unit is used to control the second switching unit to be in the first state when the third switching unit is in the on or off state.

[0011] In some embodiments of this disclosure, a fifth resistor is provided between the control terminal of the second switching unit and the third switching unit.

[0012] In some embodiments of this disclosure, the current limiting circuit further includes a sixth resistor and a seventh resistor connected in series, with the end of the sixth resistor away from the seventh resistor connected to the controller, the end of the seventh resistor away from the sixth resistor grounded, and the control terminal of the third switching unit connected between the sixth resistor and the seventh resistor.

[0013] According to a second aspect of the present disclosure, a current limiting chip is provided, including the current limiting circuit as described in the first aspect.

[0014] According to a third aspect of the present disclosure, an electronic device is provided, including a current limiting circuit as described in the first aspect, or a current limiting chip as described in the second aspect.

[0015] In some embodiments of this disclosure, the device further includes a power supply and an interface; the current limiting circuit or the current limiting chip is disposed between the power supply and the interface, and is used to disconnect the power supply from the power supply to the interface when the current transmitted from the power supply to the interface is greater than a preset threshold.

[0016] In some embodiments of this disclosure, the device further includes a processor configured to send a control command to the third switching unit of the current limiting circuit or the current limiting chip based on a user-input power-off command, so as to control the power supply to disconnect the power supply to the interface.

[0017] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: The current limiting circuit provided in this embodiment has a first switching unit between the input and output terminals. When the first switching unit is in the ON state, the current limiting circuit is on; when the first switching unit is in the OFF state, the current limiting circuit is off. A grounding branch, comprising multiple electrical components, is connected at one end to the input terminal and at the other end to ground. A second switching unit is located between the input terminal and the control terminal of the first switching unit. The control terminal of the second switching unit is connected between any two electrical components in the grounding branch. Therefore, when the current between the input and output terminals exceeds a preset threshold, the second switching unit will be in a first state (OFF or ON), causing the first switching unit to be in the OFF state, thus disconnecting the current limiting circuit. Therefore, this current limiting circuit can achieve high-precision and high-accuracy current limiting by configuring the number, type, and parameters of the electrical components in the grounding branch. Moreover, the device structure of this current limiting circuit is relatively simple and the cost is low. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] Figure 1 This is a schematic diagram of the current limiting circuit shown in an exemplary embodiment of the present disclosure; Figure 2 This is a schematic diagram of the phase relationship of a current limiting circuit shown in another exemplary embodiment of this disclosure; Figure 3 This is a circuit structure diagram of an electronic device illustrated in an exemplary embodiment of the present disclosure; Figure 4 This is a structural block diagram of an electronic device illustrated in an exemplary embodiment of the present disclosure. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0021] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0022] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0023] Based on the technical problems mentioned in the background art, in a first aspect, at least one embodiment of this disclosure provides a current limiting circuit that can monitor the current from its input terminal to its output terminal in real time and disconnect the input terminal from the output terminal when the current exceeds a preset threshold, thereby avoiding damage to the relevant electrical components in the device due to excessive current and thus protecting the safety of the electrical components.

[0024] For example, this current limiting circuit can be applied in electronic devices, such as on the power supply line of the power supply pin of the data output interface of the electronic device (such as HDMI (High Definition Multimedia Interface)). That is, on the line where the device supplies power to the power supply pin, which is used to transmit power from the device to the device or component connected in the interface.

[0025] Please refer to the appendix. Figure 1 The diagram illustrates the structure of the current limiting circuit. The current limiting circuit includes an input terminal Vin, an output terminal Vout, a first switching unit Q1, a ground branch, and a second switching unit Q2.

[0026] The first switching unit Q1 is located between the input terminal Vin of the current limiting circuit and the output terminal Vout of the current limiting circuit. The first switching unit Q1 can be a transistor, field-effect transistor, or other similar device. The voltage difference between the end of the first switching unit Q1 connected to the input terminal Vin and the control terminal can be used to control the first switching unit Q1 to turn on or off. For example, when the voltage difference between the end of the first switching unit Q1 connected to the input terminal Vin and the control terminal is not less than a first voltage threshold, the first switching unit Q1 is off; when the voltage difference between the end of the first switching unit Q1 connected to the input terminal Vin and the control terminal is less than the first voltage threshold, the first switching unit Q1 is on.

[0027] The grounding branch includes multiple electrical components. One end of the grounding branch is connected to the input terminal Vin, and the other end is grounded to GND. The electrical components in the grounding branch can be resistors, capacitors, inductors, etc. These multiple electrical components in the grounding branch can divide the voltage at the input terminal Vin between the input terminal Vin and GND, meaning that the voltage across each electrical component is different.

[0028] The second switching unit Q2 is located between the input terminal Vin and the control terminal of the first switching unit Q1. The control terminal of the second switching unit Q2 is connected between any two electrical components in the grounding branch. The second switching unit Q2 can be a transistor, field-effect transistor, or other transistor. The voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal can be used to control the second switching unit Q2 to turn on or off. For example, when the voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal is not greater than a second voltage threshold, the second switching unit Q2 is off; when the voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal is greater than the second voltage threshold, the second switching unit Q2 is on. Since the control terminal of the second switching unit Q2 is connected between any two electrical components in the grounding branch, the voltage difference between the control terminal of the second switching unit Q2 and the input terminal Vin is positively correlated with the current between the input terminal Vin and the output terminal Vout.

[0029] Preferably, the first switching unit Q1 is a PMOS transistor, with its source connected to the input terminal Vin (directly or indirectly), its gate connected to the first switching unit Q1, and its drain connected to the output terminal Vout. The PMOS transistor is turned on when the voltage difference between its source and gate is not less than a first voltage threshold; the PMOS transistor is turned off when the voltage difference between its source and gate is less than the first voltage threshold; and when the gate is turned on to the input terminal Vin, the voltage difference between the gates is less than the first voltage threshold.

[0030] Preferably, the second switching unit Q2 is an NPN transistor, with its emitter connected to the input terminal Vin, its base connected to the circuit between the two electrical components in the ground branch, and its collector connected to the control terminal of the second switching unit Q2. When the voltage difference between its emitter and base is not greater than a second voltage threshold, the transistor is off; when the voltage difference between its emitter and base is greater than the second voltage threshold, the transistor is on.

[0031] Based on the above circuit structure, the control terminal of the second switching unit Q2 is used to control the second switching unit Q2 to be in a first state (either an open or closed state) when the current between the input terminal Vin and the output terminal Vout is greater than a preset threshold; the control terminal of the first switching unit Q1 is used to control the first switching unit Q1 to be in an open state when the second switching unit Q2 is in the first state. The control terminal of the second switching unit Q2 is used to control the second switching unit Q2 to be in a second state (either an open or closed state) when the current between the input terminal Vin and the output terminal Vout is not greater than a preset threshold; the control terminal of the first switching unit Q1 is used to control the first switching unit Q1 to be in a closed state when the second switching unit Q2 is in the second state.

[0032] For example, if the current between the input terminal Vin and the output terminal Vout is not greater than a preset threshold, the voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal is not greater than a second voltage threshold, and the second switching unit Q2 is disconnected. Therefore, the voltage difference between the end of the first switching unit Q1 connected to the input terminal Vin (directly or indirectly) and the control terminal is not less than a first voltage threshold, and the first switching unit Q1 is turned on. If the current between the input terminal Vin and the output terminal Vout is greater than the preset threshold, the voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal is greater than the second voltage threshold, and the second switching unit Q2 is turned on. Therefore, the second switching unit Q2 connects the input terminal Vin to the control terminal of the first switching unit Q1. Therefore, the voltage difference between the end of the first switching unit Q1 connected to the input terminal Vin (directly or indirectly) and the control terminal is less than the first voltage threshold, and the first switching unit Q1 is disconnected, meaning the current limiting circuit is disconnected and cut off.

[0033] The current limiting circuit provided in this embodiment has a first switching unit Q1 between the input terminal Vin and the output terminal Vout. When the first switching unit Q1 is in the on state, the current limiting circuit is on; when the first switching unit Q1 is in the off state, the current limiting circuit is off. A grounding branch, including multiple electrical components, is connected at one end to the input terminal Vin and at the other end to ground GND. A second switching unit Q2 is located between the input terminal Vin and the control terminal of the first switching unit Q1. The control terminal of the second switching unit Q2 is connected between any two electrical components in the grounding branch. Therefore, when the current between the input terminal Vin and the output terminal Vout exceeds a preset threshold, the second switching unit Q2 will be in a first state, i.e., off state or on state, and the first switching unit Q1 will be in the off state, thus causing the current limiting circuit to disconnect. Therefore, this current limiting circuit can achieve high-precision and high-accuracy current limiting by configuring the number, type, and parameters of the electrical components in the grounding branch. Moreover, the device structure of this current limiting circuit is relatively simple and the cost is low.

[0034] In some embodiments of this disclosure, please refer to the appendix. Figure 1 A first resistor R1 is also provided between the input terminal Vin and the grounding branch. This avoids the grounding branch being directly connected to the input terminal Vin, which would result in a high voltage at one end of the grounding branch. Preferably, the first resistor R1 can be simultaneously provided between the input terminal Vin and the first switching unit Q1, thereby avoiding a voltage drop between the input terminal Vin and the output terminal Vout.

[0035] The grounding branch includes a second resistor R2 and a third resistor R3 connected in series, and the control terminal of the second switching unit Q2 is connected between the second resistor R2 and the third resistor R3.

[0036] The control terminal of the first switching unit is connected to a fourth resistor R4, with the end of the fourth resistor R4 furthest from the first switching unit grounded to GND. This prevents the input terminal Vin from being directly grounded to GND when the second switching unit Q2 is turned on.

[0037] This embodiment divides the voltage between the input terminal Vin and ground using the first resistor R1, the second resistor R2, and the third resistor R3. This makes the voltage difference between the end of the second switching unit Q2 connected to the input terminal Vin and the control terminal positively correlated with the current in the first resistor R1. Therefore, high-precision and high-accuracy current limiting can be achieved by configuring the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3, that is, the current can be disconnected in time when the current reaches the preset threshold.

[0038] In some embodiments of this disclosure, please refer to the appendix. Figure 2The current limiting circuit further includes a third switching unit Q3, which is located between the control terminal of the second switching unit Q2 and ground GND. The control terminal of the third switching unit Q3 is connected to the controller MCU and is used to control the third switching unit Q3 to be in a conducting state or a disconnected state based on the instructions of the controller MCU. The control terminal of the second switching unit Q2 is used to control the second switching unit Q2 to be in a first state when the third switching unit Q3 is in a conducting state or a disconnected state.

[0039] For example, a fifth resistor R5 is provided between the control terminal of the second switching unit Q2 and the third switching unit Q3. This prevents the control terminal of the second switching unit Q2 from being directly grounded to GND when the third switching unit Q3 is turned on.

[0040] For example, the current limiting circuit also includes a sixth resistor R6 and a seventh resistor R7 connected in series. The end of the sixth resistor R6 away from the seventh resistor R7 is connected to the controller MCU, and the end of the seventh resistor R7 away from the sixth resistor R6 is grounded to GND. The control terminal of the third switching unit Q3 is connected between the sixth resistor R6 and the seventh resistor R7.

[0041] For example, the GPIO pin of the controller MCU is connected to the control terminal of the third switch unit Q3 to input a high or low level to the control terminal of the third switch unit Q3, thereby controlling the third switch unit Q3 to be turned on or off. R6 and R7 form a voltage divider resistor between the controller MCU and ground, so that when the controller MCU outputs a high level, the control terminal of Q3 connected between R6 and R7 will be at a high level.

[0042] It should be understood that the above examples can be combined with each other.

[0043] Preferably, the third switching unit Q3 is an NPN transistor or an NMOS transistor, with its source or emitter connected to the control terminal of the second switching unit Q2, its base or gate connected to the controller MCU (directly or indirectly), and its collector or drain grounded to GND. Its base or gate conducts between the control terminal of the second switching unit Q2 and ground GND when the controller MCU outputs a high level, and is turned off when the controller MCU outputs a low level; alternatively, its base or gate conducts between the control terminal of the second switching unit Q2 and ground GND when the controller MCU outputs a low level, and is turned off when the controller MCU outputs a high level.

[0044] In this embodiment, when the controller MCU outputs a low level through the GPIO pin, the third switch unit Q3 is turned off. Therefore, the circuit structure added in this embodiment does not affect the circuit structure provided in the previous embodiment. That is, the current limiting circuit responds to the current between the input terminal Vin and the output terminal Vout being turned on or off. When the controller MCU outputs a high level through the GPIO pin, the third switch unit Q3 is turned on. The control terminal of the second switch unit Q2 is grounded to GND through the third switch unit Q3. Therefore, the voltage difference between the end of the second switch unit Q2 connected to the input terminal Vin and the control terminal will be greater than the second voltage threshold. Thus, the second switch unit Q2 will turn on the input terminal Vin and the control terminal of the first switch unit Q1, thereby turning off the first switch unit Q1.

[0045] It should be understood that this embodiment, based on the current limiting circuit's cut-off response to excessive current from input Vin to output Vout, further adds an active cut-off function. That is, the controller MCU can actively trigger the current limiting circuit to cut off by outputting a high or low level, thus disconnecting the conduction between input Vin and output Vout. This allows devices using this current limiting circuit to disconnect power in certain scenarios, thereby reducing power consumption and avoiding the need for hot-swapping under adverse conditions.

[0046] The effect of avoiding hot-plugging under costly conditions is explained as follows: When the current limiting circuit is applied to the power supply line of the power supply pin of the data output interface of an electronic device, if no device is connected to the data output interface, the current limiting circuit is still conducting, and the device is hot-plugged when connected to the data output interface, which may cause damage to the interface and the connected device to a certain extent. However, this embodiment can cut off the current limiting circuit when no device is connected to the data output interface, thereby stopping the power supply to the power supply pin, so the device is not hot-plugged when connected to the data output interface.

[0047] According to a second aspect of the present disclosure, a current limiting chip is provided, including the current limiting circuit as described in the first aspect.

[0048] According to a third aspect of the present disclosure, an electronic device is provided, including a current limiting circuit as described in the first aspect, or a current limiting chip as described in the second aspect.

[0049] In some embodiments of this disclosure, the device further includes a power supply and an interface; the current limiting circuit or the current limiting chip is disposed between the power supply and the interface, and is used to disconnect the power supply from the power supply to the interface when the current transmitted from the power supply to the interface is greater than a preset threshold.

[0050] In some embodiments of this disclosure, the device further includes a processor configured to send a control command to the third switching unit of the current limiting circuit or the current limiting chip based on a user-input power-off command, so as to control the power supply to disconnect the power supply to the interface.

[0051] Please refer to the appendix. Figure 3 The diagram illustrates a portion of the device's circuit structure, using the example of a device's power supply providing power to an HDMI interface. The processor can be a microprocessor such as an MCU, and the power supply can be a charging interface or a battery, providing 5V to the HDMI interface. The first switching unit of the current-limiting circuit or current-limiting chip within the device forms a power switch section and is connected to both the power supply and the HDMI interface. The second switching unit forms a transistor control section, and the third switching unit forms a GPIO control section. The transistor control section can control the power switch section to turn on or off based on the voltage provided by the power supply; that is, it controls the power switch section to turn off when the voltage is too high and to turn on when the voltage is not too high. The GPIO control section can actively control the power switch to turn on or off through the transistor control section under the control command of the MCU.

[0052] Please refer to the appendix. Figure 4 The diagram illustrates, for example, a block diagram of an electronic device. For instance, device 400 could be a mobile phone, computer, digital broadcasting terminal, messaging device, game console, tablet device, medical device, fitness equipment, personal digital assistant, etc.

[0053] Reference Figure 4 The device 400 may include one or more of the following components: a processing component 402, a memory 404, a power supply component 406, a multimedia component 408, an audio component 410, an input / output (I / O) interface 412, a sensor component 414, and a communication component 416.

[0054] Processing component 402 typically controls the overall operation of device 400, such as operations associated with display, telephone calls, data communication, camera operation, and recording. Processing component 402 may include one or more processors 420 to execute instructions to perform all or part of the steps of the methods described above. Furthermore, processing component 402 may include one or more modules to facilitate interaction between processing component 402 and other components. For example, processing component 402 may include a multimedia module to facilitate interaction between multimedia component 408 and processing component 402.

[0055] Memory 404 is configured to store various types of data to support the operation of device 400. Examples of this data include instructions for any application or method operating on device 400, contact data, phonebook data, messages, pictures, videos, etc. Memory 404 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0056] The power supply component 406 provides power to the various components of the device 400. The power supply component 406 may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power to the device 400.

[0057] Multimedia component 408 includes a screen that provides an output interface between the device 400 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touchscreen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, swipe, and gestures on the touch panel. The touch sensors may sense not only the boundaries of the touch or swipe action but also the duration and pressure associated with the touch or swipe operation. In some embodiments, multimedia component 408 includes a front-facing camera and / or a rear-facing camera. When the device 400 is in an operating mode, such as a shooting mode or a video mode, the front-facing camera and / or the rear-facing camera may receive external multimedia data. Each front-facing camera and rear-facing camera may be a fixed optical lens system or have focal length and optical zoom capabilities.

[0058] Audio component 410 is configured to output and / or input audio signals. For example, audio component 410 includes a microphone (MIC) configured to receive external audio signals when device 400 is in an operating mode, such as call mode, recording mode, and voice recognition mode. The received audio signals may be further stored in memory 404 or transmitted via communication component 416. In some embodiments, audio component 410 also includes a speaker for outputting audio signals.

[0059] I / O interface 412 provides an interface between processing component 402 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include, but are not limited to, home buttons, volume buttons, power buttons, and lock buttons.

[0060] Sensor assembly 414 includes one or more sensors for providing status assessments of various aspects of device 400. For example, sensor assembly 414 may detect the on / off state of device 400, the relative positioning of components such as the display and keypad of device 400, changes in the position of device 400 or a component of device 400, the presence or absence of user contact with device 400, the orientation or acceleration / deceleration of device 400, and temperature changes of device 400. Sensor assembly 414 may also include a proximity sensor configured to detect the presence of nearby objects without any physical contact. Sensor assembly 414 may also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, sensor assembly 414 may also include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor.

[0061] Communication component 416 is configured to facilitate wired or wireless communication between device 400 and other devices. Device 400 can access wireless networks based on communication standards, such as WiFi, 2G or 3G, 4G or 5G, or combinations thereof. In one exemplary embodiment, communication component 416 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 416 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0062] In an exemplary embodiment, device 400 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components.

[0063] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0064] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A current limiting circuit, characterized in that, The current limiting circuit includes: The first switching unit is located between the input terminal and the output terminal of the current limiting circuit; A grounding branch includes multiple electrical components, one end of which is connected to the input terminal and the other end is grounded. The second switching unit is located between the input terminal and the control terminal of the first switching unit, and the control terminal of the second switching unit is connected between any two electrical components of the grounding branch. Wherein, the control terminal of the second switching unit is used to control the second switching unit to be in a first state when the current between the input terminal and the output terminal is greater than a preset threshold, wherein the first state is an open state or an on state; the control terminal of the first switching unit is used to control the first switching unit to be in an open state when the second switching unit is in the first state.

2. The current limiting circuit according to claim 1, characterized in that, The control terminal of the second switching unit is used to control the second switching unit to be in a second state when the current between the input terminal and the output terminal is not greater than a preset threshold. The second state is either an on state or an off state. The control terminal of the first switching unit is used to control the first switching unit to be in an on state when the second switching unit is in the second state.

3. The current limiting circuit according to claim 1, characterized in that, A first resistor is also provided between the input terminal and the grounding branch.

4. The current limiting circuit according to claim 1, characterized in that, The grounding branch includes a second resistor and a third resistor connected in series, and the control terminal of the second switching unit is connected between the second resistor and the third resistor.

5. The current limiting circuit according to claim 1, characterized in that, The control terminal of the first switching unit is connected to a fourth resistor, and the end of the fourth resistor furthest from the first switching unit is grounded.

6. The current limiting circuit according to claim 1, characterized in that, The current limiting circuit also includes a third switching unit, which is located between the control terminal of the second switching unit and ground. The control terminal of the third switching unit is connected to the controller and is used to control the third switching unit to be in a conducting state or a disconnected state based on the controller's instructions. The control terminal of the second switching unit is used to control the second switching unit to be in the first state when the third switching unit is in the on or off state.

7. The current limiting circuit according to claim 6, characterized in that, A fifth resistor is provided between the control terminal of the second switching unit and the third switching unit.

8. The current limiting circuit according to claim 6, characterized in that, The current limiting circuit also includes a sixth resistor and a seventh resistor connected in series. The end of the sixth resistor away from the seventh resistor is connected to the controller, and the end of the seventh resistor away from the sixth resistor is grounded. The control terminal of the third switching unit is connected between the sixth resistor and the seventh resistor.

9. A current limiting chip, characterized in that, Includes the current limiting circuit as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, It includes the current limiting circuit as described in any one of claims 1 to 8, or the current limiting chip as described in claim 9.

11. The electronic device according to claim 10, characterized in that, The device also includes a power supply and an interface; the current limiting circuit or the current limiting chip is located between the power supply and the interface, and is used to disconnect the power supply from the power supply to the interface when the current transmitted from the power supply to the interface is greater than a preset threshold.

12. The electronic device according to claim 11, characterized in that, The device further includes a processor, which is configured to send a control command to the third switching unit of the current limiting circuit or the current limiting chip based on a power-off command input by the user, so as to control the power supply to disconnect the power supply to the interface.

Images